1. Field of the Invention.
This invention is generally related to work-holder devices for spark plugs and particularly to a combination work-holder and packaging device in which a plurality of spark plugs of varying sizes may be frictionally received and supported in an orderly relationship having the electrode portion of each spark plug disposed outwardly from a supporting surface.
2. Description of the Prior Art.
Heretofore there have been many efforts directed to providing work-holder devices and packaging devices which are particularly adapted for retaining and/or displaying spark plugs. Due to the possibility of damage to the fragile electrode portion of spark plugs, it has long been a practice in the industry to provide packaging which affords the electrode some amount of protection from impact. In prior art packaging devices the electrode is protected against damage by the provision of specially designed supporting sleeves which are spaced from the bottom of the packaged container. U.S. Pat. No. 3,276,574 to Meyers and U.S. Pat. No. 3,554,369 to Paschke disclose two such packaging devices in which the spark plug is retained having its electrode portion supported by specially contoured openings in the container so that the electrode is spaced from the bottom of each of the respective packages.
In addition to the necessity of providing specially designed packages for the sale and distribution of spark plugs, it has also been recognized and much inventive effort has been directed to specially designed storage racks in which a plurality of spark plugs may be carried and/or stored for repair, emergency or other uses. As in the packaging art, the provision of storage racks for spark plugs has met with the same problem of providing a suitable retaining means which not only supports the individual spark plugs but does so in such a manner that damage to the electrode portion of the spark plug is prevented. In many such prior art storage rack devices, such as those disclosed in U.S. Pats. Nos. 1,404,958 to Hobbs and 1,391,471 to Gomez, the spark plugs are securely mounted by threaded engagement with specially designed socket portions of the racks so that their electrode portions are spaced from any surface against which a possible impact would cause damage to the electrode. However, such racks are often bulky and costly to construct and may require intricate spark plug retaining means such as the threaded support of the above mentioned prior art structures.
In addition to the packaging and storage devices discussed above, periodic maintenance which is required of most internal combustion engines necessitates the removal, inspection and maintenance of the engine's spark plugs. In this regard it is frequently the practice when performing maintenance on a piece of equipment to remove the plugs, place them carefully in a position on a supporting surface so that the electrodes will not be damaged and then inspect the plugs one by one, checking both the condition of the plug and also for a variety of telltale signs which the electrodes'condition may reflect about the possible problem areas in the cylinders from which the plugs were removed.
In this regard, the haphazard removal of spark plugs from the engine and their random placement on a working surface may often be counterproductive to the proper maintenance of the vehicle and the spark plugs themselves. Specifically the careful inspection of each of the electrode areas of the respective spark plugs will often indicate the malfunctioning of a particular cylinder. If the spark plugs have been randomly removed and placed on the working surface, there is no way to indicate to the mechanic which of the various cylinders may need special attention or maintenance. Further the random placement of a spark plug on any surface invites the possibility of damage to the electrode portion of the spark plug through an accidental impact of the electrode against a foreign object.
In addition to the proper indexing and retention of the spark plugs during their removal and maintenance, it is preferred that each spark plug be positively retained by a work-holder so that the cleaning and gapping of the spark plug can be performed with ease, accuracy and safety. Patents such as that to Zimmerman U.S. Pat. No. 1,429,669 disclose work-holders which are particularly adapted for holding various sizes of spark plugs. Such work-holders must often be clamped or supported on another surface and therefore their versatility is somewhat restricted. In addition, although each spark plug is supported by the work-holder during maintenance of an engine, there has been no provision for supporting all of the plugs in an indexed or orderly relationship which corresponds to the number of plugs and their placement within the respective cylinders of the internal combustion engine from which they were removed or into which they are to be placed.
Other examples of the prior art include U.S. Pat. No. 1,434,338 to Grose, U.S. Pat. No. 2,548,289 to Carraher, U.S. Pat. No. 3,285,410 to Brunsing, and U.S. Pat. No. 2,960,235 to Farber et al.